Stay on target

A hundred years later, the Titanic‘s maiden voyage would probably have gone a lot smoother.

Glaciers around the world have gradually shrunk since the 1960s: ice melts, filling the ocean and rising sea levels. And the process—slow but steady—will only worsen over time with the help of global warming.

Eventually, every corner of the planet will be drowning in salt water. But which glacier will be the death of your favorite major ports? The folks at NASA’s Jet Propulsion Laboratory (JPL) have an idea.

As described by a study published this week in the Science Advances journal, a new diagnosis tool—gradient fingerprint mapping (GFM)—lets anyone with an Internet connection find out which ice sheet poses the biggest threat to Abu Dhabi, Wilmington, or any of the other 291 evaluated cities in between.

New Yorkers, for example, are most susceptible to shifts in the northeastern parts of the Greenland Ice Sheet (those furthest away), suggesting that proximity is not the leading indicator of risky icebergs.

The science gets even weirder when you consider other effects: The change in ocean water depth surrounding areas where there’s a large enough ice loss will actually drop, because there is less gravitational pull.

See for yourself with GFM; aimed at coastal planners, the interactive data visualization and simulation tool is open to the general public. Simply click and drag across the map to change views; scroll or pinch to zoom in and out. Click “Let’s Go” in the bottom right corner to navigate directly to an exact location.

“It’s a lens for that particular city into the complex interactions between the ice, the ocean, the perturbations to the gravity field from changes in ice mass, elastic rebound of the Earth as the ice melts, and [a disturbance] to the rotation of the Earth itself,” study lead and JPL researcher Eric Larour told Geek in an email.

Larour and co-authors Erik Ivins and Surendra Adhikari apply GFM to 293 major port cities, allowing local architects and designers to calculate and plan for possible sea-level adjustments.

“We hope this will allow coastal planners to step away from the assumption that any ice melting contributes just [to] global mean sea level, but rather has a very specific way of affecting cities locally,” Larour added.